Back when Marlon Brando brayed “Stel-llla!” in “A Streetcar Named Desire,” chances are no one in the audience yelled, “I’m over here!” And when he — and a succession of other Stanleys — asked, “Mind if I make myself comfortable?,” the response wasn’t a heartfelt “Oh yeah, baby!”

But it’s another day, another “Streetcar” — and the latest revival of Tennessee Williams’ classic, opening tonight at the Broadhurst Theatre, is headed by a very buff Blair Underwood. While his Stanley is no more polished — though a lot less Polish — than his predecessors, Underwood’s drawing a new and audibly excited audience to his Broadway debut.

“Sometimes the shouting’s a little disrupting, but he deserves it,” says Nicole Ari Parker, who plays Blanche, the faded beauty, to the former “LA Law” star’s beast. “It keeps us on our toes.”

The other day in his dressing room — dominated by a big family portrait with his wife, Desiree, and their three children — Underwood is gracious, warm and, alas, fully clothed, in a corduroy jacket, jeans and long-sleeved tee. Words like “grateful,” “lucky” and “honored” tumble from his lips. Told about the “Hallelujahs!” that erupted after he doffed his T-shirt at a recent performance, he laughs.

How does a 47-year-old manage to look so hot? “I have to stay in the gym and work out,” says Underwood, who lately does most of his eating onstage — pork chops, potatoes and oranges, some of which he hurls, Stanley-like, to the floor.

“When I read the script, I knew I had to take my shirt off, so I had to make sure I wasn’t gonna give the audience a juice pack.”

A juice pack?

“Yeah, a gut, a belly.” He laughs. “You don’t want to see that.”

You won’t. What you will see is a provocative take on a character you thought you already knew.

“You can be aware of a shadow without being haunted by it,” says Underwood of Brando, who was 23 when he rode “Streetcar” to stardom. “My approach is to start with the written word, this masterpiece Tennessee Williams gave us, and dig deep . . .”

He hadn’t even seen the movie — or read the play — until two years ago. Two years before that, he’d vied to play Brick in an all-black production of Williams’ “Cat on a Hot Tin Roof.” The role went to Terrence Howard, hot off an Oscar nod for “Hustle & Flow,” but Underwood caught the eye of producer Stephen C. Byrd, who thought he’d make a good Stanley.

While this is Broadway’s first multiracial “Streetcar” — Daphne Rubin-Vega plays Stanley’s wife, Stella; Amelia Campbell, their white neighbor, Eunice — Underwood believes the playwright would have been pleased. “People would love to project onto Tennessee Williams that he’d be turning over in his grave,” Underwood says. “That couldn’t be further from the truth! [Director] Emily Mann knew Tennessee Williams, and they had conversations about this. I saw an interview in which he said, ‘I always felt I was black.’ In 1956, an all-black cast did [‘Streetcar’] in LA. It’s just never been done on Broadway.”

Underwood grabs the script and reads the opening stage directions: “ ‘Two women, one white, one colored, are taking the air . . . For New Orleans is a cosmopolitan city where there’s an easy mingling of races.’ He knew this world.”

With the Williams’ estate’s blessings, they’ve made adjustments: Gone is any mention of “Polacks” and the name Kowalski. Nor is there a reference to the famed eatery Galatoire’s, which was segregated in the late 1940s; instead, Stanley, Stella and friends head to the integrated Dooky Chase’s.

As far as Underwood’s concerned, Stanley isn’t a redneck: He’s a blue-collar guy who may suffer from post-traumatic stress syndrome after years in the service — like the buttoned-up Navy pilot the actor played on TV’s “In Treatment.”

“Stanley’s a fascinating character because he’s a man-child,” says Underwood, whose father was an Army colonel. “The fact is, he’s incredibly vulnerable. His values are his wife, his baby on the way — and anything or anyone that threatens it, he’ll shut it down. He’ll destroy it.”

Stanley destroys Blanche, bending her over, face-down, on a kitchen table in a rape scene that, at a recent matinee, drew gasps and nervous laughter.

Underwood’s wife and children — ages 10, 13 and 15 — saw the final dress rehearsal before heading home to Los Angeles. While he made sure the kids left before the rape scene, he says they were shocked by how “mean” his Stanley was.

“He’s volcanic, he’s mercurial,” Underwood says, “and I can’t wait to get onstage with this character every night.”